My source file for connecting a PIC to an IDE disk is here: test.c
It is written/developed in Hi-Tech PICC. The Hi-Tech provided delay.c and delay.h are also
part of the project.

What it does:

Use serial port 19200, N81, and HyperTerminal as user interface, press h for help
Basic I/O routines: read and write registers
Configure drive
Get drive information (manufacturers part number string, cyls, heads and sects)
Read and write sectors
Stream data to and from media at 8kHz for my digital answering machine project

What it doesn't do:

Any sort of FAT, only records onto a certain area at the moment
Use LBA addressing mode (don't need it myself - yet)
Handle every possible drive error
Packet modes, UDMA-100 etc, the advanced high speed stuff, sort of need an ASIC, not a PIC!

The code is dependent on my hardware configuration. Here is a brief description of the
IDE bus rather than a schematic, which I will post 'later' (never):

IDE INTERFACE PART	My Circuit
16 Bit Bidirectional data bus	PORTB ('IDE_DATA_LOW') and PORTC ('IDE_DATA_HIGH')
3 Bit Register Address bus	PORTE ('IDE_ADDR')
/WRITE	PORTC bit 0 ('IDE_WR')
/READ	PORTC bit 1 ('IDE_RD')
/CS0	PORTC bit 2 ('IDE_CS0')
/CS1	PORTC bit 3 ('IDE_CS1')
/RST	PORTC bit 4 ('IDE_RST')

I also have a DAC connected on IDE_DATA_LOW in my app.

To understand the signals, registers, commands, which to use and when, and what the response
will be, I strongly recommend you go here:
http://www.piclist.com/techref/drives.htm
and read 'How to connect an IDE disk to a microcontroller using an 8255'. This guide is not as
complete as a standards document, but it is logical and easy to understand.

See: